low fps and quick drops

[mike167890]

I just built my 1st  system  i5 7500 with a RX 480 windows 10 I been having an issue where no matter what resolution I run or graphics quality  it jumps from ~80 to 30 fps quick jumps I have all the latest drivers etc the system runs much higher demanding games like the witcher 3 and fallout 4 with no problems ,and I have a cheap laptop that has an 5th gen i3 and intel HD graphics that runs the game much better on low. I have all the latest drivers and stuff  this card should run the game at 1080p high settings around ~100-140fps 

so does anyone have any suggestions?